This is a study of subarachnoid hemorrhage which aims to: a) continue to bring to bear on the problem their special expertise in hemodynamic studies using the dye dilution technique, which is unique in that it allows a determination of all parameters (flow, cerebral blood volume, transit time and total, arteriolar and venous resistance); b) continue the study of SAH in this model which lends itself to both acute and chronic serial flow studies, production of SAH at will and in which blood and CSF sample can be easily obtained or drugs administered; c) study in depth the hemodynamic changes and the clinical correlates; d) quantitate the effects of 4 different therapeutic approaches (neurogenic, vasorelaxent, kallikrein inhibition, inactivation of spasmogenic agents) on cerebral hemodynamics, metabolism and morbidity and mortality; e) hopefully establish a body of knowledge on which to intelligently base treatment of this castastrophic event in man.